\begin{tikzpicture}[node distance=2cm, auto,>=latex', thick]
    \tikzstyle{tool} = [draw, thin, fill=blue!20, minimum width=7em, text width=6em, text centered]
    \tikzstyle{data} = [ellipse, draw, thin, fill=green!20, minimum width=5em, text width=5em, text centered]
    \tikzstyle{human} = [rectangle, thin, minimum height=7em, minimum width=2.5em ,text width=2em]

    \node[human,label=below:{\scriptsize Programator}] (om) {};
    \node[data, above of=om, xshift=3.5cm] (cod) {\scriptsize Cod};
    \node[data, below of=om, xshift=3.5cm] (spec) {\scriptsize Proprietate};
    \node[tool, right of=om, xshift=5cm] (proof_gen) {\scriptsize Generare dem.};
    \node[data, below of=proof_gen] (proof) {\scriptsize Demonstra\c tie};
    \node[tool, right of=proof_gen, xshift=2cm] (proof_check) {\scriptsize Verificare};
    \node[data, below of=proof_check] (yes_no) {\scriptsize DA / NU};
    \node[data, above of=proof_check] (semant) {\scriptsize Semantic\u a};

    \path[->] (om) edge node[above left] {\scriptsize Limbaj de}
                        node[left] {\scriptsize programare} (cod);
    \path[->] (om) edge node[left] {\scriptsize Limbaj de}
                        node[below left] {\scriptsize specificare} (spec);
    \path[->] (om) edge node[above] {\scriptsize Limbaj de}
                        node[below] {\scriptsize demonstra\c tie}  (proof_gen);
    \path[->] (cod) edge (proof_gen);
    \path[->] (spec) edge (proof_gen);
    \path[->] (proof_gen) edge (proof);
    \path[->] (proof) edge (proof_check);
    \path[->] (proof_check) edge (yes_no);
    \path[->] (semant) edge (proof_check);

    \path [draw] (om.north) + (0,-0.7cm) circle (0.2cm);                % cap
    \path [draw] (om.north) + (0,-0.9cm) -- + (0,-1.5cm);               % corp
    \path [draw] (om.north) + (-0.5cm,-1cm) -- + (+0.5cm,-1cm);         % maini
    \path [draw] (om.north) + (0,-1.5cm) -- + (-0.5cm,-2cm);            % picior st
    \path [draw] (om.north) + (0,-1.5cm) -- + (+0.5cm,-2cm);            % picior dr

\end{tikzpicture} 